iOS Simulator cannot create devices after upgrading to Xcode 6

I just recently upgraded to XCode 6.1.1 from 5.1.1. When I launch iOS Simulator. I get an error "Unable to boot device in current state: Creating". I have tried deleting the devices and adding them back manually. But that is to no avail. I have reinstalled XCode as well after uninstalling and cleaning my Library and Preferences folders. That also has not worked. I am not sure if there are artifacts left over from 5.1.1 that are causing this.

Does anyone know what the root cause/solution is?

Please Advise